Piezoelectric Positioning Device Dual Digital Analog Converters
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Solution Overview
Problem
Piezoelectric actuators face limitations in achieving high positioning accuracy due to the dependence on digital/analog converter quantization levels and voltage levels, leading to inaccuracies and noise that affect their performance.
Innovation Solution
A piezoelectric positioning device utilizing two digital/analog converters, a coarse converter with a larger voltage range and a fine converter with a smaller range, where the fine converter's voltage levels are significantly lower, allowing for increased accuracy by compensating for inaccuracies and noise, and a low-pass filter to attenuate noise and maintain dynamic response.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single digital/analog converter is used to control the piezoelectric actuator, then the device complexity is low, but the positioning accuracy is limited by quantization levels and voltage levels
Solution Approach 1:
The single digital/analog converter is segmented into two separate converters: a first digital/analog converter with a first voltage range and a second digital/analog converter with a second voltage range. This segmentation allows each converter to operate at optimized voltage levels, with the second converter providing fine-resolution control for high positioning accuracy while the first converter handles coarse positioning, thereby resolving the contradiction between accuracy and complexity.
Solution Approach 2:
The solution adds a new dimension to the control system by introducing a second voltage range dimension alongside the first voltage range. The second digital/analog converter operates in this additional voltage dimension with finer quantization levels, enabling high-precision positioning without requiring a single complex high-voltage converter, thus resolving the accuracy-complexity trade-off.
2Measurement precision
If the second voltage range covers more first voltage levels to improve accuracy compensation, then the positioning accuracy increases, but the second voltage levels increase which may disrupt position regulation
Solution Approach 1:
The system dynamically adjusts the second voltage range parameter to optimize the balance between accuracy compensation and regulation stability. By carefully selecting the coverage of the second voltage range over the first voltage levels, the system achieves sufficient accuracy compensation while maintaining stable position regulation, resolving the contradiction between precision and reliability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables high positioning accuracy and dynamic response with reduced noise and inaccuracy, ensuring reliable and precise positioning of kinematic systems, particularly in projection exposure apparatus.
Implementation Method 1
Piezoelectric actuators are known and are used to position kinematic systems in a highly accurate manner
Implementation Method 2
a low-pass filter to attenuate noise and maintain dynamic response
Data Source
AI summary
A piezoelectric positioning device (1) has at least one piezoelectric actuator (3) having a first connection contact (4) and a second connection contact (5). A control device (6) with digital/analog converters (12, 16) connected to the connection contacts (4, 5) is used to control the at least one piezoelectric actuator (3). In comparison with a coarse converter (12), a fine converter (16) has a comparatively smaller voltage range and lower voltage levels, with the result that a high degree of positioning accuracy can be achieved.